For over 10 years, Zimbabwe has faced frequent outbreaks of typhoid and cholera, which are spread through contaminated water and food, as a result of inadequate infrastructure for water, sanitation, and hygiene (WASH). Furthermore, the country has seen an increase in the rates of drug-resistance in both diseases.
From October 2017 to February 2018, there was an outbreak of typhoid, involving over 3000 suspected cases caused by a strain of Salmonella enterica subsp enterica serovar Typhi (S Typhi) resistant to ciprofloxacin, the first-line drug for typhoid treatment in the country. In response to this outbreak, the Government undertook initiatives to improve WASH services and in February–March 2019 carried out a mass TCV immunisation campaign targeting children aged 6 months to 15 years in the outbreak-affected suburbs of Harare.
According to WHO, “The increased rates of drug-resistant typhoid called for preventive measures such as the new typhoid vaccine to help the country better protect its population, particularly its children”. Hence, in June 2021, the Zimbabwean Government, in collaboration with Gavi, the Vaccine Alliance, WHO, and UNICEF, incorporated TCV in the country’s routine immunisation schedule, in addition to the vaccination drives in 2019 and 2021.
David Sack (Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA) told The Lancet Microbe: “In the past, typhoid was considered to be a disease best treated with antibiotics. But as we have continued to use different antibiotics, the bacteria become increasingly resistant to each one. On the other hand, by using vaccines, we can prevent the infection in the first place, and this removes the need to use the antibiotic and removes the antibiotic pressure leading to resistance.”
“Given the potential of the Vi-conjugate typhoid vaccine to induce protection from clinical disease in the community rapidly, it would definitely be a prudent public health strategy,” Carl Britto (Boston Children’s Hospital, Boston, MA, USA) told The Lancet Microbe, adding: “[S Typhi,] like other Gram-negative organisms, most commonly acquires multidrug resistance via acquisition of plasmids in the context of antibiotic pressure, and a mass vaccination strategy is [a more efficient way] to decrease antibiotic pressure.
Jason Andrews (Stanford University, Stanford, CA, USA) told The Lancet Microbe: “Zimbabwe is among the first countries in the world (together with Pakistan and Liberia) to introduce TCVs. This is not only important for the people of Zimbabwe but also seeing the impact of this move will be informative to other countries deciding whether and when to prioritize TCV introduction.
Antimicrobial resistance has also been an important concern for cholera. In September 2018–March 2019, Zimbabwe saw an outbreak of cholera caused by a multidrug-resistant strain of Vibrio cholerae that involved 10 730 suspected cases and caused the Government to change the patient management guideline for the disease from recommending ciprofloxacin (an inexpensive antibiotic) to recommending azithromycin (a more expensive antibiotic). Furthermore, during the 2019 TCV distribution campaign, more than 1·5 million people in 17 suburbs of Harare also received the cholera vaccine.
According to Isaac Bogoch (University of Toronto, Toronto, ON, Canada), “Vaccines are a promising tool to combat antimicrobial resistance…Effective vaccines for infections such as typhoid, cholera (and others) ultimately reduce the incidence and impact that these infections have on communities, and reduce the need for the use (and overuse) of antimicrobial agents”.
>Despite the effects of the COVID-19 pandemic on health services in Zimbabwe, the typhoid vaccination campaign and inclusion of TCV into the routine immunisation programme have advanced across the country, and these initiatives have been praised by WHO as “a welcome development that could save countless lives.” Additionally, Zimbabwe has developed a roadmap to eliminate cholera by 2028, which mainly focuses on WASH and the strengthening of infrastructure to ensure adequate water and sanitation coverage. It also emphasises oral cholera vaccination campaigns as a complementary measure to be used in cholera hotspots.